The present invention relates to a gateway system characterized in that said gateway system provides a communication protocol conversion function and a data format conversion function which are used at the time of connection to another system connected to an open network typified by Internet, and that said gateway system itself is also connected to the open network.
A method that is conventionally and usually used to settle differences of communication protocols, data formats, etc. between systems is the following: the data formats and the communication protocols are converted using various kinds of conversion programs. For example, communication over two networks can be realized by installing a machine, which executes a program for converting a protocol on the machine, in each of the networks to perform data communication between networks that adopt a different communication protocol each other.
However, the program and the system for realizing the communication are made by each company individually for its own use. In addition, hardware, on which the gateway system operates, is also prepared by each company on its own account. Therefore, initial investment for development and operation cost were required. Moreover, because of difference between communication protocols or between data formats, it is usually required to build a gateway system separately for each destination, resulting in an increase in a cost and in a burden on humans. Therefore, if a number of destinations is many, a huge cost is required to cover all of the destinations.
By the way, as a result of a recent Internet boom, Internet exchanges, at which commodities are dealt with on Internet, become widespread. In addition to it, as regards purchase behavior of an individual, dependency on Internet is also increased. Therefore, each company encounters a situation in which the company is forced to handle business transactions on Internet. Under the circumstance, an information system is required to be connected to an open network such as Internet. However, because the conventional information system is not developed on the assumption that the information system is connected to an open network, it is necessary to modify the system profoundly, or to update the system, in order to achieve the connection. This requires a great expense. However, because of a considerable change in recent management environment, it is not easy to subsidize the expense.